1. Field of Inventions
The present inventions relate generally to scanners and, more particularly, to flatbed scanners.
2. Description of the Related Art
Desktop computers have become an integral part of most homes and offices. In order to make computers more useful, a wide variety of peripheral devices have been introduced. Peripheral devices, which are specialized devices that are connected to the computer, include CD-ROM drives, printers, audio speakers, and high capacity removable storage devices. Another popular peripheral device is the scanner. Scanners are devices that convert visible images (including text images), such as those found on individual sheets of paper, in photographs, as well as in books and other bound material, into digital data. Some scanners can even be used to generate images of a three dimensional objects.
Peripheral devices must, of course, share valuable desk space with the computer chassis (which includes the CPU) and monitor and other traditional items such as telephones and in/out boxes. This often results in clutter and leaves little to no work space on the desktop. Fortunately, in recent years, many peripheral devices have been incorporated into the computer chassis itself. For example, CD-ROM drives and high capacity removable storage devices are now commonly incorporated into the computer chassis. Speakers are often incorporated into or mounted on the computer monitor. This saves valuable desktop space. One peripheral device that continues to occupy large amounts of desktop space is the scanner and, more specifically, the so-called flatbed scanner.
Generally speaking, there are two types of desktop scanners--sheet feeding scanners and flatbed scanners. Sheet feeding scanners, as the name suggests, are designed to pull (or "feed") a sheet through a housing that includes the image scanning hardware and processing circuitry. The size of sheet feeding scanners has been steadily reduced to the point where sheet feeding scanners occupy a very small portion of the desktop.
Flatbed scanners typically include a relatively large housing and a glass covered opening (or "window") that is at least large enough to allow the placement of an 8.5 inch by 11 inch sheet thereon. The image scanning hardware and processing circuitry are located within housing. After a sheet or other image bearing substrate is placed on the glass, the image is irradiated by a light source. The reflected light sensed by an image sensor that moves past the glass covered opening and the signals generated by the sensor are processed and digitized. Although larger than sheet feeding scanners, flatbed scanners remain popular because, in addition to scanning images on sheets, flatbed scanners are able to scan images found in books and other bound material and generate images of three dimensional objects.